Endoluminal prosthesis with steerable branch

ABSTRACT

An endoluminal prosthesis may include a tubular main graft body including a sidewall and proximal and distal ends. A first stent may be positioned near the proximal end of the main graft body. A second stent may be positioned adjacent to and distal of the first stent. An opening in the sidewall may be positioned longitudinally between a peak of the first stent and a valley of the second stent. A tubular branch may be disposed in the opening. The branch may include first and second end openings. The branch may be flexibly orientable between a retrograde configuration in which the first end opening is oriented toward the distal end and the second end opening is oriented toward the proximal end and an antegrade configuration in which the first end opening is oriented toward the proximal end and the second end opening is oriented toward the distal end.

RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.13/626,166, filed Sep. 25, 2012, which claims priority and the benefitof provisional U.S. Patent Application Ser. No. 61/539,700, filed Sep.27, 2011, and provisional U.S. Patent Application Ser. No. 61/581,412,filed Dec. 29, 2011, each of which is incorporated herein by referencein its entirety.

TECHNICAL FIELD

This disclosure relates to medical devices for implantation within thehuman or animal body for treatment of endovascular disease.

BACKGROUND

The present disclosure relates generally to medical devices. Moreparticularly, it relates to an endoluminal prosthesis with a steerablebranch.

Endovascular methods have been proposed for treatment of diseases of theaorta such as aortic dissection and aortic aneurysm. Using stent graftsto treat aneurysms is common in the medical field. Stent grafts aredeployed by accessing a vasculature with a small incision in the skinand guiding a delivery system to the target area. This endoluminaldelivery is less invasive and generally preferred over more intrusiveforms of surgery. Multiple stent grafts may be implanted usingendoluminal delivery to provide a system of interconnected stent grafts.Interconnected stent grafts can be made of fenestrated stent grafts andsmaller side branch grafts, including bifurcated components.

Such methods have been proposed particularly when the diseased portionof the aorta is adjacent the aorta bifurcation. But when the diseasedportion of the aorta is located higher up in the aorta, for example, inthe region of the descending aorta adjacent the thoracic arch or in theascending aorta, endovascular techniques for treating these diseases aresomewhat more difficult because of the arched or curved nature of thethoracic arch, the presence of major arteries in the region, and theproximity to the heart.

Custom made devices, including scalloped and fenestrated devices, havebeen used in situations where the arch vessels are compromised andentire coverage of the aortic arch is not required. However, deploymentof these devices may be difficult.

SUMMARY

The present embodiments provide an endoluminal prosthesis with asteerable branch.

In one example, an endoluminal prosthesis may include a tubular maingraft body. The main graft body may include a sidewall, a proximal end,and a distal end. A first stent may be positioned near the proximal endof the main graft body. A second stent may be positioned adjacent to anddistal of the first stent. Each of the first stent and the second stentmay include a peak and a valley. The main graft body may include anopening in the sidewall positioned longitudinally between the peak ofthe first stent and the valley of the second stent. The prosthesis mayinclude a tubular branch disposed in the opening and attached to themain graft body. The branch may include a first end opening and a secondend opening. The branch may be flexibly orientable between a retrogradeconfiguration and an antegrade configuration. In the retrogradeconfiguration, the first end opening may be oriented toward the distalend of the main graft body and the second end opening may be orientedtoward the proximal end of the main graft body. In the antegradeconfiguration, the first end opening may be oriented toward the proximalend of the main graft body and the second end opening may be orientedtoward the distal end of the main graft body.

In another example, an endoluminal prosthesis may include a main tubulargraft body. The main graft body may include a proximal end and a distalend. The main graft body may include a slit extending at least partiallycircumferentially around the main graft body. The prosthesis may includea tubular branch disposed in the slit. The branch may include a firstportion extending inward from the main graft body, a second portionextending outward from the main graft body, ad an intermediate portionattached to the main graft body adjacent to the slit. The second portionof the branch may be flexibly orientable toward the proximal end or thedistal end of the main graft body.

In another example, a method of treating a body vessel may includeintroducing an endoluminal prosthesis into the body vessel. Theprosthesis may include a tubular main graft body. The main graft bodymay include a sidewall, a proximal end, and a distal end. The main graftbody may include an opening in the sidewall of the main graft body. Theprosthesis may include a tubular branch disposed in the opening andattached to the main graft body. The branch may include a first endopening and a second end opening. The first end opening may be flexiblyorientable toward the proximal end or the distal end of the main graftbody. The method may include introducing a balloon into the branch tomove the branch into a desired orientation relative to the graft body.The method may include deploying a branch prosthesis within the branchin the desired orientation to connect the prosthesis to a branch vessel.

Other systems, methods, features, and advantages of the invention willbe, or will become, apparent to one with skill in the art uponexamination of the following figures and detailed description. It isintended that all such additional systems, methods, features, andadvantages be within the scope of the invention, and be encompassed bythe following claims.

BRIEF DESCRIPTIONS OF THE DRAWINGS

FIG. 1 is a perspective view of one embodiment of an endoluminalprosthesis.

FIG. 2 is a perspective view of one embodiment of an endoluminalprosthesis with a branch in a retrograde configuration and a preloadedcatheter.

FIG. 3 is a perspective view of the endoluminal prosthesis of FIG. 2with the catheter further advanced within the branch.

FIG. 4 is a perspective view of the endoluminal prosthesis of FIGS. 2-3with a balloon deployed in the branch to adjust an orientation of thebranch.

FIG. 5 is a perspective view of the endoluminal prosthesis of FIGS. 2-4with the balloon deployed in the branch and the branch in an antegradeconfiguration.

FIGS. 6-11 illustrate various embodiments of stent configurations foruse on an endoluminal prosthesis.

FIGS. 12-13 illustrate a side view and a top view, respectively, of oneembodiment of an endoluminal prosthesis having one exemplary stentconfiguration and a slanted proximal end.

FIGS. 14-15 illustrate a side view and a top view, respectively, of oneembodiment of an endoluminal prosthesis having one exemplary stentconfiguration and a slanted proximal end.

FIGS. 16-17 are perspective views of one embodiment of an endoluminalprosthesis with a branch prosthesis deployed therein.

FIG. 18 is a perspective view along a lumen of the endoluminalprosthesis of FIGS. 16-17 with the branch prosthesis deployed therein.

FIGS. 19-20 illustrate different embodiments of retention arrangementsfor constraining a proximal end of a prosthesis.

FIG. 21 illustrates one embodiment of an introducer having a curvedcannula.

FIG. 22 illustrates one embodiment of an introducer having a curveddilator tip.

FIGS. 23-24 depict one embodiment of an endoluminal prosthesis having abranch.

FIG. 25 depicts a lumen of the endoluminal prosthesis of FIGS. 23-24from a proximal end of the prosthesis.

FIG. 26 depicts the endoluminal prosthesis of FIGS. 23-24 with thebranch in a retrograde configuration and a branch prosthesis deployedtherein.

FIG. 27 depicts the endoluminal prosthesis of FIGS. 23-24 with thebranch in an antegrade configuration and a branch prosthesis deployedtherein.

FIG. 28 depicts a lumen of the endoluminal prosthesis of FIGS. 23-24with a branch prosthesis deployed therein.

FIGS. 29-30 depict one embodiment of a trough formed in an endoluminalprosthesis and a branch extending from the trough.

FIGS. 31-32 depict one embodiment of an endoluminal prosthesis having atrough and a branch.

FIG. 33 depicts a lumen of the endoluminal prosthesis of FIGS. 31-32from a distal end of the prosthesis.

FIG. 34 depicts a lumen of the endoluminal prosthesis of FIGS. 31-32from a proximal end of the prosthesis.

DETAILED DESCRIPTION OF THE DRAWINGS AND THE PRESENTLY PREFERREDEMBODIMENTS

The present disclosure relates to an endoluminal prosthesis with asteerable branch.

In the present disclosure, the term “proximal” refers to a directionthat is generally closest to the heart during a medical procedure, whilethe term “distal” refers to a direction that is farthest from the heartduring a medical procedure.

FIGS. 1-5 depict one example of a prosthesis 10. In one example, theprosthesis 10 may be configured as a single branch thoracic endograftthat provides flow to the left subclavian artery or the left commoncarotid artery as further described below. In other examples, theprosthesis 10 may be applied to extend coverage more proximal by usingthe single branch for the left common carotid artery and relying on flowthrough the vertebrals or an extra-attomic bypass to maintain flow tothe left subclavian artery. The prosthesis 10 may be applicable to treataneurysms and/or dissections that require more proximal coverage than astandard thoracic stent graft might allow. The prosthesis 10 may includea graft body 20. The graft body 20 may include a graft material 22having an inner surface 23 and an outer surface 24. The graft body 20may be configured as a generally tubular member having a substantiallycylindrical shape. The inner surface 23 of the graft material 22 maydefine a main lumen 26 extending longitudinally within the graft body 20between a proximal end 27 and a distal end 28 thereof. The main lumen 26may be suitable for passing a fluid such as, for example, bloodtherethrough.

The graft material 22 may be made of any material known in the art.Preferably, the graft material 22 may be formed from a biocompatiblematerial that is substantially non-toxic in the in vivo environment ofits intended use and substantially unrejected by the patient'sphysiological system (i.e., is non-antigenic). For example, the graftmaterial 22 may be made of an expanded polytetrafluoroethylene (ePTFE),polytetrafluoroethylene (PTFE), silicone, polyurethane, polyamide(nylon), polyethylene, polypropylene, polyaramids, polyacrylonitrile,cellulose, or another flexible biocompatible material. The graftmaterial 22 also may be made of known fabric graft materials, e.g.,woven polyester such as DACRON® from Invista (Wichita, Kans.),polyetherurethanes such as THORALON® from Thoratec Corporation(Pleasanton, Calif.), or polyethylene such as an ultra-high molecularweight polyethylene (UHMwPE) such as DYNEEMA® from DSM Dyneema LLC(Stanley, N.C.). Additionally, or alternatively, materials that are notinherently biocompatible may be subjected to surface modifications torender the materials biocompatible. Examples of surface modificationsmay include, for example, graft polymerization of biocompatible polymerson the surface, coating of the surface with a crosslinked biocompatiblepolymer, chemical modification with biocompatible functional groups, orimmobilization of a compatibilizing agent such as heparin or otherbiocompatible substances. Thus, any fibrous material having sufficientstrength to survive in the in vivo environment may be used to form atextile graft, provided the final textile is biocompatible.

The graft material 22 may include a bioremodelable material such asreconstituted or naturally-derived collagenous materials, extracellularmatrix (ECM) material, submucosa, renal capsule membrane, dermalcollagen, dura mater, pericardium, fascia lata, serosa, peritoneum orbasement membrane layers, or intestinal submucosa, including smallintestinal submucosa (SIS), stomach submucosa, urinary bladdersubmucosa, or uterine submucosa. One non-limiting example of a suitableremodelable material is SURGISIS® BIODESIGN™ from Cook Medical(Bloomington, Ind.). Another suitable remodelable material is the graftprosthesis material described in U.S. Pat. No. 6,206,931 to Cook et al.,which is incorporated herein by reference in its entirety. Additionally,or alternatively, the graft material 22 may be made of any of thematerials described in U.S. Pat. No. 7,407,509 to Greenberg et al. orU.S. Patent Application Pub. No. 2009/0171451 by Kuppurathanam et al.,which are incorporated herein by reference in their entirety.

The graft body 20 may include at least one support structure 30, such asa stent. The support structure 30 may be configured as a single, unitarystructure or a plurality of independent structures. The supportstructure 30 and/or various portions thereof may be disposed on theinner surface 23 and/or the outer surface 24 of the graft material 22.Multiple support structures 30 may be positioned at one or more pointsalong a length of the graft body 20. One or more support structures 30may be positioned proximate the proximal end 27 and/or the distal end 28of the graft body 20 to seal the respective ends of the graft bodyagainst a wall of a body vessel. The support structures 30 positionedproximate the proximal end 27 and/or the distal end 28 of the graft body20 may be positioned on the inner surface and/or the outer surface ofthe graft body 20. In some instances, it may be desirable to affix oneor more of the stents to an internal surface of a prosthesis. Forexample, in complex anatomical situations, stents affixed to an externalsurface of a prosthesis may have the potential to become intertwinedwith the wires or other devices utilized to ensure branch vessel access,sealing, or fixation.

The support structures 30 and/or various portions thereof may be stentshaving any suitable stent pattern known in the art. The stents may beballoon expandable. Preferably, the stents may be self-expandable. Thestents can maintain the patency of the prosthesis and ensure adequatesealing against the surrounding vascular tissue. Some of the goals forstent design and placement, whether internal or external, may includepreventing metal-to-metal contact points, preventing contact between twodifferent types of alloys, and minimizing micromotion. Preferably, stentsizing, spacing, and design may be determined so that there is nostent-to-stent contact even in tortuous anatomy. Stents preferably maybe placed to maximize prosthesis flexibility while maintaining patency,as well as reducing material wear and stent fatigue. Furthermore, it maybe preferable that the stents do not interfere with any branches of theprosthesis, as further described below, that they minimize the potentialfor galvanic corrosion, and that they ensure adequate joint stability.Stent amplitude, spacing, and stagger preferably may be optimized foreach prosthesis design. Any of the stents mentioned herein may havebarbs and/or other anchoring members to help decrease the potential forprosthesis migration. Barbs may limit migration of the prosthesis 10.Additionally, or alternatively, barbs may reduce the potential forcrushing or dislodging the branch 60 which may be caused by migration ofthe prosthesis 10 relative to a branch vessel. In some situations, suchas treatment of an aortic dissection, it may be desirable for theprosthesis 10 to be particularly atraumatic. To that end, barbs may beomitted from the prosthesis 10 in some embodiments.

One example of a stent pattern is the Z-stent or Gianturco stent design.Each Z-stent may include a series of substantially straight segments, orstruts, interconnected by a series of bent segments, or bends. The bentsegments may include acute bends or apices. The Z-stents may be arrangedin a zigzag configuration in which the straight segments are set atangles relative to one another and are connected by the bent segments.This design provides both significant radial force as well aslongitudinal support. In tortuous anatomy, branches, or fenestrations,it may be preferable to use alternative stents or modifications to theZ-stent design to avoid stent-to-stent contact. Alternative stents mayinclude, for example, annular or helical stents.

The stents described herein may be made from any suitable material knownin the art. In one example, the stents may be made from standard medicalgrade stainless steel and may be soldered using silver standard solder(0 lead/0 tin). In other examples, the stents may be made from ametallic material selected from any type of stainless steel, silver,platinum, palladium, gold, titanium, tantalum, iridium, tungsten,cobalt, chromium, cobalt-chromium alloy 1058, cobalt-based 35N alloy,nickel-based alloy 625, a molybdenum alloy, a molybdenum alloy includingabout 0.4% to about 0.8% of lanthanum oxide (La₂O₃), and anickel-titanium alloy, or other suitable materials known in the art. Thestents may be made from nitinol or other shape-memory metal. Moreover,the stents may be configured in a variety of ways to provide a suitableintraluminal support structure. For example, one or more stents may bemade from a woven wire structure, a laser-cut cannula, individualinterconnected rings, or another pattern or design.

A deformable region 40 may be disposed on the graft material 22 of thegraft body 20. The deformable region 40 may include a biocompatiblegraft material 42. The graft material 42 may be formed from any materialknown in the art. For example, the graft material 42 may be formed fromany of the materials described above with reference to the graftmaterial 22. The graft material 42 may be formed from the same or adifferent material than the material used to form the graft material 22.The deformable region 40 may be formed integrally with the graft body20. To that end, the graft material 22 and the graft material 42 may beformed from a unitary piece of graft material. The deformable region 40may be formed during a weaving process used to produce the unitary pieceof graft material. For example, a number of warp yarns and/or a numberof weft yarns may be adjusted during the weaving process to form excessgraft material as described in U.S. Patent Application Pub. No.2010/0063576 by Schaeffer et al., which is incorporated by referenceherein in its entirety.

Additionally, or alternatively, the deformable region 40 may be attachedto the graft body 20. The deformable region 40 may be attached to thegraft body 20 by sutures, wire, staples, clips, bonding agents, or othermethods that may be used to achieve a secure attachment. For example,the deformable region 40 may be attached to the graft body 20 by anymethod described in U.S. Patent Application Pub. No. 2006/0095118 byHartley, which is incorporated by reference herein in its entirety. Thedeformable region 40 may be attached to the graft material 22 and/or thesupport structure 30 of the graft body 20. Preferably, the graftmaterial 42 of the deformable region 40 may be attached to the graftmaterial 22 of the graft body 20 to form a fluid-tight seal. Forexample, the graft material 42 of the deformable region 40 may bestitched to the graft material 22 of the graft body 20. An opening maybe formed through the graft material 22 of the graft body 20 and maycorrespond to the deformable region 40. The deformable region 40 may bepositioned within the opening such that an inner surface 43 of thedeformable region is generally contiguous with the inner surface 23 ofthe graft body 20 and an outer surface 44 of the deformable region isgenerally contiguous with the outer surface 24 of the graft body. Inother words, the deformable region 40 may be positioned within theopening such that the inner surface 43 is in communication with thelumen 26 of the graft body 20.

An outer edge of the deformable region 40 may be defined by a perimeter46. The perimeter 46 may be positioned within a space defined by one ormore of the support structures 30 of the graft body 20. For example, afirst proximal stent 30 a may be positioned proximate the proximal end27 of the graft body 20 as shown in FIG. 1. The first proximal stent 30a may be disposed on the inner surface 23 of the graft material 22. Asecond proximal stent 30 b may be positioned proximate and distal to thefirst proximal stent 30 a. The second proximal stent 30 b may bedisposed on the inner surface 23. The first proximal stent 30 a may havea series of peaks 32 a formed by proximal bends and a series of valleys34 a formed by distal bends. Similarly, the second proximal stent 30 bmay have a series of peaks 32 b formed by proximal bends and a series ofvalleys 34 b formed by distal bends. The first and second proximalstents 30 a, 30 b may be positioned relative to one another such that apeak 32 a of the first proximal stent is aligned with a valley 34 b ofthe second proximal stent along a circumference of the graft body 20.The first proximal stent 30 a and the second proximal stent 30 b may bearranged on the graft body 20 to be mirror images of one another withrespect to a circumference of the graft body as shown in FIG. 1.

The first proximal stent 30 a may be positioned near the proximal end 27of the graft body 20. In one example, a peak 32 a of the first proximalstent 30 a may be spaced from the proximal end 27 of the graft body 20by a distance of less than about 2 mm, typically between about 0.5 mmand about 1 mm. The proximity of the first proximal stent 30 a to theproximal end 27 of the graft body 20 may reduce the amount ofunsupported graft material at the proximal end of the graft body. Thismay reduce the probability of graft infolding and/or movement of thegraft material (e.g., in response to blood flow), which may cause graftfatigue. In other examples, the first proximal stent 30 a may be spacedany suitable distance from the proximal end of the graft body.

Additionally, or alternatively, the first proximal stent 30 a and thesecond proximal stent 30 b may be spaced longitudinally from one anotherby a distance (e.g., between a valley 34 a and a peak 32 b) of betweenabout 2 mm and about 20 mm, typically between about 5 mm and about 13mm. In one example, the spacing between the first proximal stent 30 aand the second proximal stent 30 b may vary circumferentially around thegraft body 20. For example, a top longitudinal length of the prosthesismay be greater than a bottom longitudinal length of the prosthesis(e.g., to form a slanted end as further described below). The spacingbetween the first proximal stent 30 a and the second proximal stent 30 balong the top longitudinal length may be greater than the spacingbetween the first proximal stent and the second proximal stent along thebottom longitudinal length. In one example, the first proximal stent 30a and the second proximal stent 30 b may be spaced longitudinally fromone another by a distance of between about 5 mm and about 15 mm,typically between about 7 mm and about 13 mm, preferably about 10 mmalong the top longitudinal length. Additionally, or alternatively, thefirst proximal stent 30 a and the second proximal stent 30 b may bespaced longitudinally from one another by a distance of between about 2mm and about 7 mm, typically about 5 mm along the bottom longitudinallength. The spacing between other portions of the support structure 30(e.g., between other adjacent stents) may be similar to the spacingbetween the first proximal stent 30 a and the second proximal stent 30b. In other examples, adjacent stents may be spaced any suitabledistance from one another.

The perimeter 46 of the deformable region 40 may correspond to a spacegenerally bounded on its proximal sides by one peak 32 a and the twoadjacent struts of the first proximal stent 30 a and on its distal sidesby one valley 34 b, which may be in alignment with the one peak 32 a,and the two adjacent struts of the second proximal stent 30 b. In thismanner, the graft material 42 of the deformable region 40 positionedwithin the perimeter 46 may be unstented. In other words, the supportstructure 30 of the graft body 20 may be positioned substantiallyoutside of the deformable region 40. The lack of support structurewithin the perimeter 46 of the deformable region 40 may enable the graftmaterial 42 to deform as further described below.

The perimeter 46 may include a frame 48. The frame 48 may add structuralsupport to the deformable region 40 and/or the attachment between thegraft material 42 of the deformable region and the graft material 22 ofthe graft body 20. The frame 48 may be configured as a rigid,semi-rigid, or flexible frame. Preferably, the frame 48 may be aflexible frame formed from any material known in the art including, forexample, the materials described above with reference to the supportstructure 30. The perimeter 46 may have any desired geometric shape. Forexample, the perimeter 46 may have a diamond shape as shown in FIGS.1-5. The diamond shape may be generally defined by the struts and bendsof the first and second proximal stents 30 a, 30 b as described above.The diamond shape may include a long axis extending substantiallyparallel to the longitudinal axis of the graft body 20 and a short axisextending substantially perpendicular to the longitudinal axis of thegraft body. Alternatively, the perimeter 46 may have a circular,triangular, rectangular, or any other polygonal or non-polygonalgeometric shape. Preferably, the perimeter 46 may be disposedsubstantially between the support structure 30 of the graft body 20regardless of the shape of the perimeter. This may provide asubstantially unstented deformable region 40 to enable deformation ofthe graft material 42 within the perimeter 46.

As best shown in FIGS. 2-5, the graft material 42 of the deformableregion 40 may be deformable within the perimeter 46. For example, thegraft material 42 may be bunched, folded, pleated, gathered, stretched,or otherwise manipulated within the perimeter 46. To that end, the graftmaterial 42 may be configured as an elastic material. Suitable elasticmaterials may include polymers such as polyeurethanes. Additionally, oralternatively, the graft material 42 may be woven in a suitable mannerto provide elastic properties to the graft material. Alternatively, oradditionally, the deformable region 40 may include excess graft material42 to enable deformation. For example, a piece of graft material 42 usedto form the deformable region 40 may have a larger surface area than thearea within the perimeter 46. Thus, excess graft material 42 may bedisposed within the perimeter 46 of the deformable region 40 when thepiece of graft material 42 is attached to or formed with the graftmaterial 22 of the graft body 20 as described above. This excess graftmaterial may enable movement of the graft material 42 of the deformableregion 40 relative to the graft body 20.

The prosthesis 10 may include a branch 60. The branch 60 may include agraft material 62 having an inner surface 63 and an outer surface 64.The branch 60 may be configured as a generally tubular member having asubstantially cylindrical shape. The inner surface 63 of the graftmaterial 62 may define a branch lumen 66 extending longitudinally withinthe branch 60 between a first end 67 and a second end 68 thereof.

The graft material 62 may be formed from any material known in the art.For example, the graft material 62 may be formed from any of thematerials described above with reference to the graft material 22 and/orthe graft material 42. The graft material 62 may be formed from the sameor a different material than the material used to form the graftmaterial 22 and/or the graft material 42. The branch 60 may be formedintegrally with the graft body 20 and/or the deformable region 40. Tothat end, the graft material 22, the graft material 42, and/or the graftmaterial 62 may be formed from a unitary piece of graft material.Alternatively, the branch 60 may be attached to the deformable region 40and/or the graft body 20. The branch 60 may be attached to thedeformable region 40 and/or the graft body 20 by sutures, wire, staples,clips, bonding agents, or other methods that may be used to achieve asecure attachment including, for example, the methods described abovewith reference to the deformable region 40. In another example, thebranch 60 may be unattached to the deformable region 40.

The branch 60 may include at least one support structure 70. The supportstructure 70 may include a single, unitary structure or a plurality ofindependent structures. The support structure 70 and/or various portionsthereof may be disposed on the inner surface 63 and/or the outer surface64 of the branch 60. Multiple support structures 70 may be positioned atany points along a length of the branch 60. In one example, the supportstructure 70 may be configured as a helical stent extending generallylongitudinally and circumferentially along the branch 60. The supportstructure 70 also may be configured as one or more annular ringspositioned along the length of the branch 60. Alternatively, oradditionally, any other type of stent including, for example, thosedescribed above in reference to the support structure 30 may be used.The support structure 70 may be formed from any material known in theart including, for example, the materials described above with referenceto the support structure 30.

The branch 60 may extend through an aperture 50 formed in the deformableregion 40. The branch 60 may extend between a position within the lumen26 of the graft body 20 and a position external to the graft body. Forexample, the branch 60 may include a first portion 72 and a secondportion 74 as best shown in FIGS. 6, 8, and 10. The first portion 72 ofthe branch 60 may extend longitudinally from the first end 67 to anintermediate point 73 positioned longitudinally between the first endand the second end 68 of the branch. The second portion 74 of the branch60 may extend longitudinally between the intermediate point 73 and thesecond end 68 of the branch. The first portion 72 of the branch 60 maybe positioned within the lumen 26 of the graft body 20. The secondportion 74 of the branch 60 may be positioned external of the graft body20. The intermediate point 73 may be generally aligned with the graftmaterial 42 of the deformable region 40. The branch 60 may be attachedto the deformable region 40 at about the intermediate point 73. A lengthof the first portion 72 of the branch 60 may range from 0 to 100% of thetotal length of the branch. A length of the second portion 74 of thebranch 60 may range from 0 to 100% of the total length of the branch. Inother words, the branch 60 may be positioned entirely within the lumen26, entirely external to the graft body 20, or partially within thelumen 26 and partially external to the graft body. In one embodiment,the length of the first portion 72 is about 50% of the total length ofthe branch 60, and the length of the second portion 74 is about 50% ofthe total length of the branch. In other words, about half of the lengthof the branch 60 may be positioned within the lumen 26 of the graft body20, and about half of the length of the branch may be positionedexternal to the graft body. In another embodiment, the length of thefirst portion 72 is about 30% of the total length of the branch 60, andthe length of the second portion 74 is about 70% of the total length ofthe branch. In other words, about 30% of the length of the branch 60 maybe positioned within the lumen 26 of the graft body 20, and about 70% ofthe length of the branch may be positioned external to the graft body.

Positioning a portion of the branch 60 within the lumen 26 of the graftbody 20 and a portion of the branch external to the graft body mayprovide multiple advantages. For example, such positioning of the branch60 may aid in moving or toggling the branch 60 into various differentconfigurations relative to the graft body 20 as further described below.Additionally, or alternatively, such positioning of the branch 60 mayaid in placement of a branch prosthesis within the branch lumen 66 toconnect the branch 60 to a target branch vessel. Positioning a largerportion of the branch 60 within the lumen 26 of the graft body 20 mayease movement of the branch relative to the graft body. Positioning alarger portion of the branch 60 external to the graft body 20 mayimprove blood flow within the lumen 26 and/or reduce branch fatigue thatmay be caused by blood flowing past the portion of the branch within thelumen of the graft body. Thus the relative lengths of the first portion72 of the branch 60 and the second portion 74 of the branch may beselected to optimize the flexibility of the branch while maintainingfluid flow within the lumen 26 of the graft body 20 and minimizingbranch fatigue.

The branch 60 may be disposed at any suitable position within thedeformable region. In one example, the branch 60 may be substantiallycentered within the deformable region. For example, the branch 60 may bepositioned approximately at the intersection of the major axis and theminor axis of the diamond-shaped deformable region. Positioning thebranch 60 approximately at the center of the deformable region may aidin providing a greater range of motion of the branch relative to thegraft body as further described below. In other examples, the branch 60may be positioned at any longitudinal and/or circumferential positionbetween adjacent support structures (e.g., the first proximal stent 30 aand the second proximal stent 30 b). In one example, the branch may bepositioned longitudinally between a peak and a valley of a supportstructure (e.g., the first proximal stent 30 a or the second proximalstent 30 b). In this manner, the branch may be positioned closer to orfarther from the proximal end of the graft body.

The branch 60 may be movable with respect to the graft body 20. Forexample, the branch 60 may be attached to the deformable region 40. Thegraft material 42 of the deformable region 40 may be deformed to changethe orientation of the branch 60 relative to the graft body 20. In oneexample, the branch 60 may be movable between a retrograde configurationand an antegrade configuration. FIGS. 2-4 depict the prosthesis 10 withthe branch 60 in the retrograde configuration. In the retrogradeconfiguration, the branch 60 may extend at an angle relative to thelongitudinal axis of the graft body 20 with the opening of the secondend 68 directed proximally and away from the outer surface 24 of thegraft body external to the graft body. Accordingly, the opening of thefirst end 67 of the branch 60 may be directed distally and away from theinner surface 23 of the graft body 20 within the lumen 26. The anglebetween the outer surface 24 and the branch 60 in the retrogradeconfiguration may range from about 0 to about 180 degrees. FIG. 5depicts the prosthesis 10 with the branch 60 in the antegradeconfiguration. In the antegrade configuration, the branch 60 may extendat an angle relative to the longitudinal axis of the graft body 20 withthe opening of the second end 68 directed distally and away from theouter surface 24 of the graft body external to the graft body.Accordingly, the opening of the first end 67 of the branch 60 may bedirected proximally and away from the inner surface 23 of the graft body20 within the lumen 26. The angle between the outer surface 24 and thebranch 60 in the antegrade configuration may range from about 0 to about180 degrees.

The branch 60 may be placed into the retrograde configuration, theantegrade configuration, or any other position between the retrogradeconfiguration and the antegrade configuration. In other words, thebranch 60 may be positioned at any angle with respect to the outersurface 24 of the graft body 20. The graft material 42 of the deformableregion 40 may be moved relative to the graft material 22 of the graftbody 20 as described above to enable movement of the branch 60 relativeto the graft body. The shape of the perimeter 46 of the deformableregion may be selected to bias or guide the branch 60 along a desiredpath of movement. For example, the diamond shaped perimeter 48 may biasthe branch 60 toward a position along a long axis of the perimeter(i.e., an axis between proximal and distal points of the diamond). Inother words, the opening of the second end 68 of the branch may bebiased toward a plane passing through the long axis of the perimeter 48and the longitudinal axis of the graft body 20. In this manner, thebranch 60 may be configured to toggle along the plane between theretrograde and antegrade configurations. Lengthening the long axis ofthe diamond shaped perimeter may increase the range of motion of thebranch 60 relative to the graft body 20 in the longitudinal direction(e.g., along the long axis of the perimeter). Conversely, shortening thelong axis of the diamond shaped perimeter may shorten the range ofmotion of the branch 60 relative to the graft body 20 in thelongitudinal direction. Likewise, lengthening the short axis (i.e., theaxis generally transverse to the long axis) of the diamond shapedperimeter may increase the range of motion of the branch 60 relative tothe graft body 20 in the circumferential direction (e.g., along theshort axis of the perimeter). Conversely, shortening the short axis ofthe diamond shaped perimeter may shorten the range of motion of thebranch 60 relative to the graft body 20 in the circumferentialdirection. The perimeter may be configured such that the branch 60 has agreater range of motion in the longitudinal direction than in thecircumferential direction.

Although the branch 60 may be biased toward a particular direction, thebranch may be movable in any direction relative to the graft body 20.For example, the branch 60 may pivot in any direction about theintermediate point 73, which may be attached to the graft material 42 ofthe deformable region 40, relative to the graft body 20. The openings ofthe first and/or second ends 67, 68 of the branch 60 may be directed inany direction (e.g., proximal, distal, or transverse) relative to thelongitudinal axis of the graft body 20.

In another example, the flexibility of the deformable region 40 mayenable the branch 60 to be placed in a desired orientation relative tothe graft body 20 of the prosthesis 10, and the branch may remainoriented as desired after adjustment. In other words, the branch 60 maynot be pulled or biased toward any orientation relative to the graftbody 20.

In another embodiment, the deformable region 40 may be omitted from theprosthesis 10, and the branch 60 may be attached to the graft body 20 asshown in FIGS. 23-28. The branch 60 may be attached to a region of thegraft body 20 defined between two adjacent stents (e.g., the first andsecond proximal stents). The region may be an unstented area between theadjacent stents. The graft material of the region of the graft body maybe held in tension between the adjacent stents. For example, the regionbetween the adjacent stents may not include excess graft material asdescribed above with reference to the deformable region 40. The branch60 may extend through a slit 29 formed in the graft body 20. Forexample, a cut may be made in the graft material of the graft body 20 toform the slit 29, and the branch 60 may be placed through the slit.

In one example, the slit 29 may extend between adjacent struts of astent (e.g., the first proximal stent) as shown in FIG. 23. This may aidin positioning the branch near the proximal end of the graft body 20 asfurther described below. Additionally, or alternatively, placement ofthe slit between adjacent struts (e.g., longitudinally at leastpartially between a peak and a valley of the stent) may aid insupporting the branch positioned within the slit. For example, the graftmaterial disposed longitudinally between a peak and a valley may be heldunder greater tension than the graft material that is not disposedlongitudinally between a peak and a valley (e.g., graft material that isdisposed longitudinally distal of the valleys of the first proximalstent 30 a and proximal of the peaks of the second proximal stent 30 b).Placement of the branch 60 in a portion of the graft material undergreater tension may aid in supporting the branch and/or biasing thebranch toward a neutral configuration (e.g., between the antegrade andretrograde configurations) as shown in FIG. 23. Placement of the branchin a portion of the graft material under lesser tension may enable agreater range of motion of the branch relative to the graft body (e.g.,by enabling greater movement of the graft material adjacent to the slit)and/or reduce the biasing force exerted on the branch.

The branch 60 may be attached to the graft body 20 adjacent to the slit29. The position of the branch 60 within the slit 29 may cause a portionof the branch 60 adjacent to the slit to deform. In other words, theportion of the graft body 20 adjacent to the slit 29 may squeeze thebranch 60 to deform a portion of the branch. In one example, thedeformed portion of the branch 60 adjacent to the slit 29 may have anelliptical shape as shown in FIGS. 23-25. In other examples, thedeformed portion of the branch may have any other shape. This may aid inenabling the branch to move or pivot about the slit between theretrograde and antegrade configurations.

The slit may have a length, which may extend circumferentially along thegraft body 20. In other examples, the length of the slit may extendlongitudinally along the graft body 20, or in any other directionrelative to the graft body. The slit may be substantially linear withrespect to the surface of the graft body 20. For example, the slit maybe configured as a linear slit extending circumferentially along thegraft body 20 in a direction transverse to the longitudinal axis of thegraft body. Alternatively, the slit may have an arcuate shape or anyother suitable shape with respect to the surface of the graft body 20.The length of the slit may be less than or equal to about ½ of thecircumference of the branch 60. Additionally, or alternatively, thelength of the slit may be greater than or equal to about ⅖ of thecircumference of the branch 60. Preferably, the length of the slit mayrange from about ⅖ of the circumference of the branch 60 to about ½ ofthe circumference of the branch. In one example, the diameter of thebranch 60 may be between about 6 mm and about 14 mm, typically betweenabout 8 mm and about 12 mm. In one example, the diameter of the branch60 may be about 8 mm (e.g., the branch may be configured as an 8 mmreinforced tube), and the length of the slit may be about 12.5 mm. Inone example, the length of the branch 60 may be between about 8 mm andabout 15 mm. In other examples, the branch may have any suitablediameter and/or length. Additionally, or alternatively, the size of theslit may be selected according to the diameter of the branch asdescribed above.

The size of the slit relative to the branch 60 may aid in securing thebranch to the graft body 20. For example, the length of the slit may besufficiently small, as compared to the circumference of the branch 60,that the branch is engaged (e.g., frictionally engaged) by the graftbody 20 at the slit. The graft material of the graft body 20 may besufficiently flexible to enable the branch 60 to move generally asdescribed above. The spacing between the adjacent stents may besufficiently large to enable such flexibility. In other words, anunsupported longitudinal section of the graft material of the graft body20 between the adjacent stents may be sufficiently flexible to enablemovement of the branch. Additionally, or alternatively, the slit mayenable movement of the branch 60 relative to the graft body 20. Forexample, the slit may be configured to enable the graft material of thegraft body 20 adjacent to the slit to move (e.g., inward or outward withrespect to the longitudinal axis of the graft body). Such movement ofthe graft material adjacent to the slit may enable movement of thebranch 60 as described above. For example, the branch 60 may beconfigured to pivot about the slit between the retrograde configurationand the antegrade configuration as described above. In this embodiment,the branch may have less of a tendency to sit in the aortic lumen. Inone example, the branch may be biased toward one of the retrogradeconfiguration and the antegrade configuration. In other examples, thebranch may be substantially unbiased. In other words, the graft materialof the graft body 20 may be sufficiently flexible that the graftmaterial does not exert a biasing force on the branch 60. The branch 60may be disposed partially within the lumen 26 of the prosthesis 10 andpartially external to the prosthesis as described above. Alternatively,the branch 60 may be disposed entirely within the lumen 26 of theprosthesis 10 or entirely external to the prosthesis also as describedabove.

In one example, the branch 60 may be positioned near the proximal end 27of the graft body 20. For example, the branch 60 may be placed betweenabout 5 mm and about 30 mm, between about 10 mm and about 25 mm, orbetween about 15 mm and about 20 mm from the proximal end 27 of thegraft body 20. Additionally, or alternatively, the graft body 20 mayhave a length, for example, ranging from about 10 cm to about 200 cm.Additionally, or alternatively, the branch 60 may be spaced from theproximal end 27 of the graft body 20 by between about 0.25% and about30%, between about 0.5% and about 25%, or between about 0.75% and about20% of the length of the graft body. The proximity of the branch 60 tothe proximal end 27 of the graft body 20 may aid in aligning the branchwith a branch vessel (e.g., the subclavian artery) while landing theproximal end of the graft body between two adjacent branch vessels(e.g., the subclavian artery and the carotid artery) without occludingthe branch vessels as shown in FIG. 21.

In one example, the branch 60 may remain substantially linear uponmovement between the retrograde configuration and the antegradeconfiguration. In other words, the branch may be movable between theretrograde configuration and the antegrade configuration without bendingthe branch. The movement or flexibility of the graft materialsurrounding the branch (e.g., the deformable region or the graftmaterial adjacent to the slit) may enable the branch to move whileremaining substantially linear.

In another embodiment, a prosthesis may include a retrograde branch asshown in FIGS. 29-34. The retrograde branch may include a trough portion60 a and a tubular branch portion 60 b. The tubular branch portion maybe configured, for example, as a 7 mm×18 mm internal spiral branch. Thetrough portion and the branch portion may be formed from a piece ofgraft material as shown in FIG. 29. At least a portion of the piece ofgraft material may be rolled into a generally tubular shape to form thebranch portion. A section of graft material may be removed from a regionof the prosthesis positioned between first and second proximal stents ofthe prosthesis. The region may be substantially diamond shaped as shownin FIGS. 29-34. Alternatively, the region may have any other shape. Thebranch and trough configuration can be modified to accommodate first andsecond proximal stents having any configuration. The trough portion maybe configured to align generally with the struts of the first and/orsecond proximal stents. The trough portion of the retrograde branch maybe attached to the graft body of the prosthesis along a perimeter of theopening formed in the graft body by removal of the section of graftmaterial. The trough portion may be attached to the graft body of theprosthesis by any suitable method. For example, the trough portion maybe stitched to the graft material of the graft body and one or morestruts of the first proximal stent using a running blanket stitch asshown in FIGS. 30-34. Alternatively, the trough portion may be formedduring weaving of the graft material of the graft body.

The trough portion and/or the branch portion may be positioned generallywithin the lumen of the prosthesis. The branch portion may be attachedto (or integral with) and extend from the trough portion. The branchportion may extend in a generally distal direction from the troughportion as shown in FIGS. 29-34 (i.e., the branch portion may beconfigured as a retrograde branch). Alternatively, the branch portionmay extend in a generally proximal direction from the trough (i.e., thebranch portion may be configured as an antegrade branch). The end of thebranch opposite the trough may be attached to the graft body. Forexample, the end of the branch may be stitched to the graft body asshown in FIG. 32. This may aid in supporting the branch within the lumenof the prosthesis. For the branch to fit appropriately, the troughdesign may be customized to fit the branch diameter and/or length. Thisdesign may enable a target branch vessel to be perfused in a retrogrademanner. This may aid in deploying the prosthesis from a femoralapproach.

In any of the examples described herein, movement of the branch 60relative to the graft body 20 may aid in aligning the branch with abranch vessel such as, for example, the left subclavian artery. Forexample, the branch 60 may be positioned at different angles relative tothe graft body 20 to account for any misalignment between the opening inthe deformable region 40 and the branch vessel. If the prosthesis 10 isplaced such that the branch 60 is slightly proximal of the ostium of thebranch vessel, the branch may be moved into the antegrade configurationto extend generally in the direction of the branch vessel. If theprosthesis 10 is placed such that the branch 60 is slightly distal ofthe ostium of the branch vessel, the branch may be moved into theretrograde configuration to extend generally in the direction of thebranch vessel. In this manner, movement of the branch 60 may compensatefor misalignment between the branch 60 and the branch vessel upondeployment of the prosthesis 10.

Such movement of the branch 60 may aid in delivering the prosthesis 10by several different methods including femoral delivery, brachialdelivery, axillary delivery, subclavian delivery, and/or transapicaldelivery. For example, the prosthesis 10 may be delivered via thefemoral artery with the branch 60 in the retrograde position. In theretrograde position, the opening of the second end 68 of the branch 60may face proximally so that a catheter extending through the branch alsomay extend proximally. This may aid in cannulating a branch vesseland/or snaring the catheter from the branch vessel when delivering theprosthesis 10 from distal to the branch vessel. In other words, thebranch 60 may be oriented in the retrograde configuration to receive acatheter, as further described below, extending generally proximally fordelivery of the prosthesis 10 using a retrograde approach (e.g., afemoral approach).

In another example, the prosthesis 10 may be delivered using brachial,axillary, or transapical delivery with the branch 60 in the antegradeposition. In the antegrade position, the opening of the second end 68 ofthe branch 60 may face distally so that a catheter extending through thebranch also may extend distally. This may aid in cannulating a branchvessel and/or snaring the catheter from the branch vessel whendelivering the prosthesis 10 from proximal to the branch vessel. Inother words, the branch 60 may be oriented in the antegradeconfiguration to receive a catheter, as further described below,extending generally distally for delivery of the prosthesis 10 using anantegrade approach (e.g., a brachial, axillary, or transapicalapproach). The ability to move the branch 60 relative to the graft body20 may aid in delivering the prosthesis 10 from distal or proximal to atarget branch vessel (e.g., using a retrograde or an antegradeapproach). The opening of the second end 68 of the branch 60, and thusthe catheter extending through the branch, may be directed proximally ordistally to face the branch vessel regardless of whether the prosthesis10 is delivered from distal or proximal to the branch vessel. Thus, thesame prosthesis may be used regardless of the delivery approach selectedby the physician.

A common practice in treating patients with Type B dissection withconventional endografts is to use a through wire starting from thesubclavian artery, snaring the wire, and pulling the wire out thefemoral artery. In this way, the subclavian approach is used tofacilitate cannulation of the true lumen, yet allow delivery of thedevice from the femoral approach. A transapical approach would also havesimilar benefits. Specific delivery system modifications (e.g., thelocation of the cannula, the location of preloaded catheters, theorientation of the device, the length of the tip, etc.) may exist foreach delivery paradigm.

The prosthesis 10 may be sized and shaped for placement within thevasculature of a patient as further described below. The preferred sizeand shape of the prosthesis 10 depends on the anatomy in which it is tobe implanted. Physiological variables, deployment characteristics, andother factors also may contribute to the determination of a proper sizeand shape of the prosthesis 10. For example, the prosthesis 10 may havea size and shape suitable for placement in the aortic arch, and/or thedescending aorta. To that end, the prosthesis 10 may be configured forplacement within the thoracic aorta with the proximal end 27 beingplaced in the aortic arch and the distal end 28 being placed in thedescending aorta. The branch 60 may be configured to align with a branchvessel such as the left subclavian artery. The graft body 20 may have adiameter, for example, ranging from about 10 mm to about 50 mm,typically from about 22 mm to about 46 mm. The diameter of the graftbody 20 may be constant along the length thereof. Alternatively, thegraft body 20 may be tapered such that the diameter of the graft bodymay vary along the length thereof. For example, the diameter of thegraft body 20 may taper from a larger diameter to a smaller diameter ina proximal to distal direction. In one example, the graft body 20 mayhave a proximal to distal taper of up to about 10 mm. A tapered graftbody 20 may be advantageous for placement within a narrowed aorta. Sucha narrowed aorta may be common when treating aortic dissection. Thebranch 60 may have a diameter, for example, ranging from about 6 mm toabout 24 mm, typically from about 8 mm to about 12 mm. The diameter ofthe branch 60 may be constant along the length thereof. Alternatively,the branch 60 may be tapered such that the diameter of the branch mayvary along the length thereof. The prosthesis 10 may be deployed incombination with various other prostheses to effectively bridge ananeurysmal and/or dissected portion of the vasculature.

It is further contemplated that a prosthesis may have multipledeformable regions and/or multiple branches. For example, the prosthesismay have two, three, or more branches attached to one or more deformableregions positioned on the graft body. The various deformable regionsand/or branches may be positioned at different longitudinal andcircumferential positions along the graft body. In this manner, thebranches may be configured to align with, for example, the leftsubclavian, left common carotid, and/or innominate arteries.Additionally, or alternatively, the prosthesis may be configured forplacement at various other positions within the vasculature of thepatient.

One or more radiopaque markers may be included to provide radiographicvisualization of the position of the prosthesis 10 when placed in a bodyvessel of a patient. A plurality of radiopaque markers, which accordingto one example may be provided in the form of gold beads, may be coupledto the graft body 20 (e.g., the graft material 22 and/or the supportstructure 30), the deformable region 40 (e.g., the graft material 42and/or the perimeter 46), and/or the branch 60 (e.g., the graft material62 and/or the support structure 70) to facilitate imaging of variousdesired locations along the length of the prosthesis 10. The radiopaquemarkers may be positioned at the proximal end 27 and/or the distal end28 of the graft body 20. The radiopaque markers also may be positionedproximate the deformable region 40 and/or the branch 60 to facilitateproper alignment with a branch vessel.

The prosthesis 10 may be provided as part of a preloaded system as shownin FIG. 2. The preloaded system may include a catheter 82, which may beconfigured to facilitate cannulation of a branch vessel, movement of thebranch 60, and/or insertion of a branch prosthesis within the branch 60.The catheter 82 may be preloaded in the prosthesis 10 prior tointroduction of the prosthesis within a patient. When preloaded as partof a delivery system, a proximal region 84 of the catheter 82 may beadvanced through the lumen 26 of the graft body 20 from the distal end28 toward the proximal end 27. The proximal region 84 of the catheter 82then may be advanced through the branch 60 to exit the prosthesis 10 asshown in FIG. 2. This configuration of the preloaded catheter 82 (i.e.,extending proximally within the prosthesis 10 from the distal end 28)may be desirable for retrograde delivery of the prosthesis (e.g.,femoral delivery). In other examples, the catheter 82 may be advancedthrough the lumen 26 from the proximal end 27 toward the distal end 28.This configuration of the preloaded catheter 82 (i.e., extendingdistally within the prosthesis 10 from the proximal end 27) may bedesirable for antegrade delivery of the prosthesis (e.g., brachial,axillary, or transapical delivery). The catheter 82 may sit in aseparate groove in a tip of a delivery device. Pulling back a sheath mayexpose the catheter 82 to allow a physician to snare and withdraw thepreloaded catheter through a sheath in the subclavian artery as furtherdescribed below. The catheter 82 may include a catch member such as ahook, loop, or eye at the proximal region 84 to aid the physician insnaring the catheter. Additionally, or alternatively, a guidewire may bereceived within a lumen of the catheter 82. The guidewire may bepreloaded in the prosthesis as described above with respect to thecatheter 82 and/or received within the preloaded catheter. The guidewiremay facilitate the placement of various other instruments, devices, orcomponents (e.g., the balloon described below) within the vasculature ofthe patient.

Various stent configurations may be used, particularly for the proximalstents, to provide a low profile prosthesis and to limit graft infoldingbetween stent points. Low profile (e.g., about 0.125 mm thick) or ultralow profile (e.g., about 0.080 mm thick) graft material and/or selectedstent configurations may provide for a delivery system diameter rangingfrom about 12 to about 20 Fr for a prosthesis having a diameter rangingfrom about 28 to about 46 mm. For example, sheath sizes of about 18 toabout 20 Fr may be possible for a 38 mm device manufactured from lowprofile materials, and sheath sizes of about 14 to about 16 Fr may bepossible for a 38 mm device manufactured from ultra low profilematerials. Delivery system sizes of approximately 18 Fr or smaller mayenable delivery from the subclavian artery in some patients. Placementof a guidewire in the true lumen when treating Type B dissection may besimplified by using subclavian delivery as opposed to femoral delivery.The ability to change the orientation of the branch 60 relative to thegraft body 20 also may aid in delivering the prosthesis 10 via thesubclavian artery (or any other forms of delivery as described above).

Several examples of proximal stent configurations are shown in FIGS.6-11. Generally, reducing the number of stent points may increase theoutward radial force provided by a prosthesis and/or reduce the profileof a prosthesis, but also may create relatively large flaps of graftmaterial between the stent points. This may increase the likelihood of aType I endoleak. Therefore, multiple stents may be placed proximate theproximal end of the graft body to provide a combination of outwardradial force and limited graft infolding.

In one example, the prosthesis 10 may include a third proximal stent 630as shown in FIGS. 6-7. The first proximal stent 30 a may be positionedon the inner surface 23 of the graft material 22 proximate the proximalend 27 of the graft body 20 as described above. The third proximal stent630 may be positioned on the outer surface 24 of the graft material 22proximate the proximal end 27 of the graft body 20. The third proximalstent 630 may be generally longitudinally aligned with the firstproximal stent 30 a. In other words, the third proximal stent 630 andthe first proximal stent 30 a may at least partially overlap one anotheron opposing surfaces of the graft material 22 of the graft body 20. Thethird proximal stent 630 may have a length or amplitude that issubstantially the same as the length or amplitude of the first proximalstent 30 a. The third proximal stent 630 may be generallycircumferentially misaligned with the first proximal stent 30 a suchthat the peaks of the first proximal stent are generally aligned withthe valleys of the third proximal stent and vice versa as bestillustrated in FIG. 6. The third proximal stent 630 may include anirregular circumferential portion 636 as shown in FIG. 7. The irregularportion 636 may be aligned circumferentially with the deformable region40 and may include an additional peak. In other words, the stent patternof the third proximal stent 630 may be disrupted in the irregularportion 636 to include an additional peak such that the third proximalstent may include one more peak than the first proximal stent 30 a. Theadditional peak of the third proximal stent 630 may be generally alignedwith the peak 32 a of the first proximal stent 30 a in alignment withthe deformable region 40 and/or the branch 60. The additional peak ofthe third proximal stent 630 may replace the valley of the thirdproximal stent that may otherwise extend into the deformable region 40.In this manner, the irregular portion 636 may modify the stent patternof the third proximal stent 640 so that the third proximal stent remainsoutside of the deformable region 40.

In this example, the first proximal stent 30 a may provide a majority ofthe outward radial force for sealing the prosthesis 10 against the wallof the body vessel. Because a majority of the outward radial force maybe applied by the first proximal stent 30 a, the third proximal stentmay be configured to apply a relatively small amount of outward radialforce. Thus, the third proximal stent 630 may be formed from a wirehaving a smaller diameter or cross sectional area than that of the firstproximal stent 30 a. The third proximal stent 630 may limit graftinfolding between the peaks of the first proximal stent 30 a and/or thethird proximal stent. The misalignment between the peaks of the firstand third proximal stents 30 a, 630 may reduce the unsupportedcircumferential lengths of graft material 22 along the proximal end 27of the graft body 20. The shorter circumferential lengths of unsupportedgraft material 22 may be less likely to fold inward, thus reducing thelikelihood of endoleak.

This stent configuration, or other stent configurations describedherein, may limit graft infolding while providing a reduced outwardradial force. The limited graft infolding may be achieved by theadditional stent points which may reduce the unsupported circumferentiallengths of graft material. The reduced outward radial force may beachieved by reducing the outward radial force applied by the thirdproximal stent (e.g., by the smaller cross sectional area of the wireused to form the third proximal stent). Such a combination of reducedoutward radial force and limited graft infolding may be desirable fortreatment of an aortic dissection. For example, this stent configurationmay provide adequate graft apposition to the aortic wall (e.g.,sufficient outward radial force) to ensure coverage of the true/falselumen communication. The reduced outward radial force applied by theprosthesis may reduce the probability of retrograde dissection. In otherwords, the outward radial force provided by the prosthesis may besufficiently large for graft apposition to the aortic wall butsufficiently small to reduce the probability of retrograde dissection.

In another example, the prosthesis 10 may include a third proximal stent830 as shown in FIGS. 8-9. The first proximal stent 30 a may bepositioned on the inner surface 23 of the graft material 22 proximatethe proximal end 27 of the graft body 20 as described above. The thirdproximal stent 830 may be positioned on the inner surface 23 of thegraft material 22 proximate the proximal end 27 of the graft body 20.The third proximal stent 830 may be positioned proximal of the firstproximal stent 30 a and may have a length, or amplitude, that is lessthan the length of the first proximal stent. In other words, the firstproximal stent 30 a and the third proximal stent 830 may have dissimilarlengths. The first proximal stent 30 a and the third proximal stent 830may be arranged in a nested relationship with one another such that noportion of the third proximal stent may overlap any portion of the firstproximal stent. The third proximal stent 830 may include twice as manypeaks and valleys as the first proximal stent 30 a. Every other peak ofthe third proximal stent 830 may be generally circumferentially alignedwith a peak of the first proximal stent 30 a. In this manner, the thirdproximal stent 830 may increase the number of stent points or peaksprovided circumferentially along the proximal end 27 of the graft body20 while remaining outside of the deformable region 40. The thirdproximal stent 830 may have any number of peaks and valleys, and is notlimited to having twice as many peaks and valleys as the first proximalstent 30 a. Preferably, the third proximal stent 830 may have a greaternumber of peaks than the first proximal stent 30 a to limit graftinfolding as described herein.

In this example, the first proximal stent 30 a may provide a majority ofthe outward radial force for sealing the prosthesis 10 against the wallof the body vessel. The third proximal stent 830 may limit graftinfolding between the peaks of the first proximal stent 30 a and/or thethird proximal stent. To that end, the third proximal stent 830 may beformed from a wire having a smaller diameter or cross sectional areathan that of the first proximal stent 30 a. The increased number ofstent points or peaks that may be provided by the third proximal stent830 may reduce the unsupported circumferential lengths of graft material22 along the proximal end 27 of the graft body 20. The shortercircumferential lengths of unsupported graft material 22 may be lesslikely to fold inward, thus reducing the likelihood of endoleak.

In yet another example, the prosthesis may include a proximal stent 1030as shown in FIGS. 10-11. The proximal stent 1030 may be positioned onthe inner surface 23 of the graft material 22 proximate the proximal end27 of the graft body 20. The proximal stent 1030 may be included insteadof the first proximal stent 30 a as shown in FIGS. 10-11. Alternatively,the proximal stent 1030 may be included in addition to the firstproximal stent 30 a. The proximal stent 1030 may include an increasednumber of peaks and valleys relative to the first proximal stent 30 a.The proximal stent 1030 may include an irregular circumferential portion1036 as shown in FIG. 11. The irregular portion 1036 may be alignedcircumferentially with the deformable region 40 and/or the branch 60.Additionally, or alternatively, the irregular portion 1036 may include awidened peak. In other words, the stent pattern of the proximal stent1030 may be disrupted (e.g., by removing a peak) in the irregularportion 1036 to include a widened peak. The bend of the widened peak mayinclude an angle that is greater than the angles of the bends of theother peaks of the proximal stent 1030. The widened peak of the proximalstent 1030 may be generally aligned with the deformable region 40 and/orthe branch 60. In this manner, the irregular portion 1036 may modify thestent pattern of the proximal stent 1030 so that the proximal stent 1030remains outside of the deformable region 40.

In this example, the proximal stent 1030 may provide the outward radialforce for sealing the prosthesis 10 against the wall of the body vessel.The proximal stent 1030 also may limit graft infolding between the peaksthereof. To that end, the additional stent points or peaks that may beprovided by the proximal stent 1030 may reduce the unsupportedcircumferential lengths of graft material 22 along the proximal end 27of the graft body 20. The shorter circumferential lengths of unsupportedgraft material 22 may be less likely to fold inward, thus reducing thelikelihood of endoleak.

The stent configurations described above, or variations or combinationsthereof, may be used at the proximal and/or distal ends of the graftbody 20. For example, multiple stents having similar lengths and beingmisaligned relative to one another may be attached to the proximal end27 and/or the distal end 28 of the graft body 20 as shown in FIGS.12-13. The stents may or may not include an irregular circumferentialportion as described above. The stent configurations described hereinmay be particularly beneficial for treating a dissected body vessel. Forexample, the stent configurations may provide adequate graft appositionto the aortic wall, ensuring coverage of the true/false lumencommunication of a dissected aorta. In some examples, the stentconfigurations also may apply a reduced radial force as compared toconventional stent grafts. This reduced outward radial force may reducethe probability of retrograde dissection.

In the embodiments illustrated in FIGS. 6-15, the graft body 20 of theprosthesis 10 may include a skewed or slanted proximal end 1227.Although not shown in FIGS. 12-15, any of these embodiments may includethe deformable region 40 and/or the branch 60 as described herein. A toplongitudinal length of the graft body 20 may be longer than a bottomlongitudinal length of the graft body to form the slanted proximal end1227. The top and bottom longitudinal lengths of the graft body 20 mayextend generally longitudinally between the proximal end 1227 and thedistal end 28 of the graft body and may be separated from one another byapproximately 180 degrees around the circumference of the graft body.

At least a portion of the top longitudinal length of the graft body 20may be configured for placement along the outer curvature of the aorticarch (e.g., the longer portion of the aortic arch). At least a portionof the bottom longitudinal length of the graft body 20 may be configuredfor placement along the inner curvature of the aortic arch (e.g., theshorter portion of the aortic arch). In other words, the shortest edgeof the device may be placed on the inner curve of the aortic arch andthe longest edge of the device may be placed on the outer curve of theaortic arch. Aligning the longer length of the graft body 20 with thelonger outer curve of the aortic arch and the shorter length of thegraft body with the shorter inner curve of the aortic arch may enhancethe ability of the prosthesis 10 to conform to the aortic anatomy upondeployment. Such enhanced conformance may enable precise, accurateplacement of the prosthesis 10 even in tortuous aortic anatomies.

The prosthesis 10 may be compressed into a delivery configuration andmounted onto a deployment device such as an introducer. Any type ofdeployment device suitable for deploying a branched stent graft may beused. For example, suitable deployment devices may include thosedescribed in U.S. Pat. Nos. 7,488,344 and 7,537,606 to Hartley et al.;U.S. Pat. No. 7,611,529 to Greenberg et al.; and U.S. Patent App. Pub.No. 2009/0204198 by Jensen et al.; which are incorporated by referenceherein in their entirety. Although the following description willgenerally refer to femoral delivery of the prosthesis 10, the prosthesis10 also may be delivered via subclavian delivery, brachial delivery,transapical delivery, axillary delivery, or any other desirable form ofdelivery. A person having ordinary skill in the art will appreciate thatthe configuration and/or orientation of the prosthesis, the deliverydevice, the preloaded catheter, and/or any components thereof may bemodified depending on the chosen delivery method. Such modifications arewithin the scope of this disclosure.

The prosthesis 10 may be radially compressed into the deliveryconfiguration on a delivery catheter and covered by an outer sheath. Todeploy the prosthesis 10, the operator may slide or retract the outersheath over the delivery catheter, thereby exposing the prosthesis. Theprosthesis may expand outwardly upon removal of the sheath. The operatormay directly manipulate the introducer, which may provide the operatorwith a relatively high degree of control during the procedure. Further,such deployment devices may be compact and may have a relativelyuniform, low-diameter radial profile, allowing for atraumatic access anddelivery.

Using such a suitable delivery system, a physician may introduce theprosthesis 10 in the delivery configuration into the femoral artery andguide the prosthesis into position within the aortic arch and/or thedescending aorta. The prosthesis 10 may be positioned using theradiopaque markers such that the branch 60 is generally aligned in thevicinity of the ostium of the left subclavian artery. The sheath of thedelivery system, which may constrain the prosthesis 10 in the deliveryconfiguration, may be retracted distally to allow the prosthesis toexpand from the delivery configuration.

The prosthesis 10 may remain at least partially restrained in a reduceddiameter configuration, for example, by one or more diameter reducingties. Diameter reducing ties may be applied to the support structure 30of the graft body 20. Preferably, diameter reducing ties may be appliedto the proximal and distal stents of the graft body 20 to retain theproximal and distal ends 27, 28 in a reduced diameter configurationafter retraction of the sheath. This may enable repositioning and/oradjustment of the prosthesis 10 prior to complete expansion of the graftbody 20, which may fix the prosthesis in place relative to the vesselwall. In one example, the diameter reducing ties may be configured asthreads looped around struts of a stent and a trigger wire. Each threadmay be pulled tight to draw the struts of the stent corresponding tothat thread closer to one another. The ends of the thread may be tiedtogether and knotted to retain the struts in place relative to thetrigger wire, thereby reducing the diameter of the stent. The struts maybe released upon removal of the trigger wire to allow expansion of thestent. The diameter reducing ties also may be configured as any othertype of constraining member capable of reducing the diameter of a stentof the prosthesis 10. For example, the diameter reducing ties may beconfigured as described in U.S. Patent App. Pub. No. 2008/0294234 byHartley et al., which is incorporated by reference herein in itsentirety.

Retraction of the sheath also may expose the preloaded catheter 82extending from the branch 60 as shown in FIG. 2. The catheter 82 may besnared and pulled though a sheath positioned within the left subclavianartery as shown in FIG. 3. A balloon may be tracked over the catheter 82and positioned within the branch 60 as shown in FIGS. 4-5. The balloonmay be manipulated to adjust the orientation of the branch 60 relativeto the graft body 20. In one example, a first end of the balloon may bepositioned within the lumen 26 of the prosthesis 10. The first end ofthe balloon may be moved proximally and/or distally relative to theprosthesis 10. Distal movement of the first end of the balloon may causethe branch 60 to move toward the retrograde configuration as shown inFIG. 4. Proximal movement of the first end of the balloon may cause thebranch 60 to move toward the antegrade configuration as shown in FIG. 5.Additionally, or alternatively, a second end of the balloon positionedexternal to the prosthesis 10 may be manipulated to adjust theorientation of the branch 60 relative to the graft body 20. In anotherexample, a catheter associated with the balloon may be manipulated(e.g., advanced, retracted, rotated, or bent) to adjust the orientationof the balloon, and thus the orientation of the branch 60, with respectto the graft body 20. The presence of the inflated balloon within thebranch 60 may provide structural stability to the branch and/or maintainpatency of the branch during adjustment. The branch 60 may be moved tothe retrograde configuration, the antegrade configuration, or any otherorientation with respect to the graft body 20, e.g., by manipulating theballoon. The orientation of the branch 60 may be adjusted to align thebranch with the left subclavian artery. Additionally, or alternatively,the orientation of the branch 60 may be adjusted to a desired positionbased on factors such as, for example, the native anatomy, plans forlater intervention (e.g., ability to easily access the descendingthoracic aorta), or any other relevant factors.

A branch prosthesis, such as a stent graft, may be deployed within thebranch 60 as shown in FIGS. 16-18. The branch prosthesis may bedelivered over the catheter 82 and deployed within the branch 60 usingany known method. The branch prosthesis may extend proximally from thebranch 60 as shown in FIG. 16, distally from the branch as shown in FIG.17, or any other direction according to the position of the branchrelative to the graft body 20. The branch prosthesis may extend betweena position within the lumen 26 of the graft body 20 and a positionexternal to the graft body as shown in FIG. 18. A lumen of the branchprosthesis may be in communication with the lumen 26 of the graft body20. In one example, the branch prosthesis may extend between the lumen26 of the graft body 20 and a branch vessel such as the left subclavianartery. In other words, a first end of the branch prosthesis may bedeployed within the branch 60 of the prosthesis 10 and a second end ofthe branch prosthesis may be deployed within the left subclavian artery.In this manner, the branch prosthesis may couple the prosthesis 10 tothe left subclavian artery to create a continuous fluid passagewaytherebetween.

The introducer may include a retention arrangement to hold at least aportion of the prosthesis 10 on the introducer. For example, theproximal end 27 of the graft body 20 may be constrained by a retentionarrangement as shown in FIG. 19. The retention arrangement may besimilar to the arrangement described in U.S. Patent Application Pub. No.2006/0004433 by Greenberg et al., which is incorporated herein byreference. Three points around the periphery of the graft body 20 may bereleasably attached to the introducer. These three points may correspondto three peaks of a proximal stent (such as the first proximal stent 30a and/or the third proximal stent 630, 830, and/or 1030). This retentionarrangement may form three lobes 1990 a, 1990 b, 1990 c of graftmaterial arranged around the introducer in a tri-fold configuration.

In another example, the proximal end 27 of the graft body 20 may beconstrained by a retention arrangement as shown in FIG. 20. Thisarrangement may be substantially similar to the arrangement shown inFIG. 19 except that multiple peaks of the proximal stent correspondingto at least one of the lobes may be releasably attached to theintroducer to form a modified tri-fold configuration such as theconfiguration shown in FIG. 20. For example, a circumferential portionof the proximal stent may correspond to the lobe 1990 a. Each of thepeaks of that circumferential portion of the proximal stent may bereleasably attached to the introducer to reduce the size of the lobe1990 a relative to the other lobes 1990 b, 1990 c. The lobe 1990 a maybe generally circumferentially aligned with the branch 60 and may beconfigured for placement along the outer curvature of the aortic arch.In other words, the lobe 1990 a having a reduced size relative to theother lobes 1990 b, 1990 c may be positioned along the greater curvatureof the aortic arch. The reduced size of the lobe 1990 a may reduce thelikelihood of the lobe 1990 a catching or snagging on a branch vesselsuch as the left subclavian artery upon deployment, positioning, and/orrepositioning of the prosthesis 10 within the aortic arch.

The introducer may be configured to enhance conformance of theprosthesis to the curvature of the aortic arch. In one example, thedelivery catheter may include a curved inner cannula 2192 as shown inFIG. 21. The curved inner cannula 2192 may be formed from a shape memorymaterial and may have a radius of curvature ranging from about 0.5 cm toabout 3.5 cm. A smaller radius of curvature may provide a greater urgingforce which may be advantageous for use in tight vascular bends. Theprosthesis 10 may be compressed into the delivery configuration andmounted to the curved cannula 2192 as described above. The curvedcannula 2192 may be held substantially straight within the sheath of theintroducer. Upon retraction of the sheath, the curved cannula 2192 mayflex toward the natural curved configuration to generally conform to thecurvature of the aortic arch. The curved cannula 2192 may push theprosthesis 10 toward the outer curvature of the aortic arch as shown inFIG. 21. Alternatively, the curved cannula 2192 may be configured topull the prosthesis 10 toward the inner curvature of the aortic arch.This may aid in conforming the prosthesis 10 to the curvature of theaortic arch and/or aligning the branch 60 with a branch vessel such asthe left subclavian artery. The branch 60 may be generallycircumferentially aligned with the greater curvature or the outercurvature of the curved cannula 2192. Thus, when the curved cannula 2192is aligned with the curvature of the aortic arch, the branch 40 may beautomatically aligned circumferentially with the branch vessels of theaortic arch. Alternatively, or additionally, the introducer may includea curved sheath. The curved sheath may generally conform to thecurvature of the aortic arch in a similar manner and with similarresults. In other words, a curved cannula or sheath may automaticallyorient the prosthesis in line with the curvature of the aorta. In thecase of arch vessels, which are generally located on the outer curve ofthe aorta, any branches can be aligned with the greater curvature of thedelivery system. When tracked into position, the system mayautomatically align the branch with the target arch vessel.

In another example, the distal end of the introducer may include acurvature to provide a self-orienting effect to the introducer. Forexample, the introducer may include a curved dilator tip 2294 as shownin FIG. 22. The prosthesis 10 may be mounted on the introducer such thatthe branch 60 may be generally circumferentially aligned with the outercurvature of the introducer. Upon placement in the aortic arch, theouter curvature of the introducer may align itself with the outercurvature of the aortic arch. This, in turn, may cause the branch 60 tobe generally circumferentially aligned with a branching vessel such asthe left subclavian artery. Such alignment may be substantiallyautomatic. In other words, the curvature of the introducer may naturallytend to align with the curvature of the aortic arch without additionalmanipulation by the physician. This automatic alignment may aid inproper positioning of the prosthesis 10 within the aortic arch. Morespecifically, rotational adjustment of the delivery device may bechallenging or even impossible, especially when a femoral approach isused. Significant tortuosity in the iliac arteries, the visceralsegment, the descending thoracic aorta, and the aortic arch may add tothe difficulty of such rotational adjustment. A means to automaticallyorient or align the delivery device and/or the prosthesis 10 within theaortic arch may help to avoid the necessity to rotate the deliverydevice, thus aiding in positioning of the prosthesis.

While various embodiments of the invention have been described, theinvention is not to be restricted except in light of the attached claimsand their equivalents. Moreover, the advantages described herein are notnecessarily the only advantages of the invention and it is notnecessarily expected that every embodiment of the invention will achieveall of the advantages described.

We claim:
 1. An endoluminal prosthesis comprising: a main graft body ofgraft material, the main graft body comprising: a sidewall, a proximalend, a distal end, and a lumen between the proximal end and the distalend; a first stent positioned near the proximal end of the main graftbody, a second stent positioned adjacent to and distal of the firststent, and a third stent distal of the second stent, each of the firststent and the second stent comprising a peak and a valley and definingan area of graft material between the peak of the first stent and thevalley of the second stent; a slit in the sidewall positionedlongitudinally between the peak of the first stent and the valley of thesecond stent and extending at least partially circumferentially aroundthe main graft body, wherein the slit has a height that is parallel to alongitudinal axis of the main graft body and a width that isperpendicular to the longitudinal axis of the main graft body, whereinthe width is greater than the height; and a tubular branch attached tothe main graft body, the tubular branch comprising a first end openingand a second end opening, the tubular branch extending from the slit andattached to the main graft body at the slit at a point of attachmentabout a circumference of the tubular branch, the tubular branch beingflexibly orientable between a retrograde configuration and an antegradeconfiguration, wherein, in the retrograde configuration, the first endopening is oriented toward the distal end of the main graft body and thesecond end opening is oriented toward the proximal end of the main graftbody, and, in the antegrade configuration, the first end opening isoriented toward the proximal end of the main graft body and the secondend opening is oriented toward the distal end of the main graft body,wherein where the point of attachment is between the first end openingand the second end opening of the tubular branch, and wherein thetubular branch has an elliptical shape at the point of attachment. 2.The prosthesis of claim 1, wherein the width of the slit comprises alength of between about ⅖ of a circumference of the tubular branch andabout ½ of the circumference of the tubular branch.
 3. The prosthesis ofclaim 1, further comprising a fourth stent positioned near the proximalend of the main graft body, the peak of the first stent comprises aseries of peaks, the valley of the first stent comprises a series ofvalleys, the fourth stent comprises a greater number of peaks andvalleys than the first stent, the fourth stent is positioned proximal ofthe first stent, and the first stent and the fourth stent are in anested relationship with one another.
 4. The prosthesis of claim 1,wherein the tubular branch further comprises a biocompatible graftmaterial and a support structure attached to the biocompatible graftmaterial of the tubular branch, and the support structure of the tubularbranch comprises at least one of a Z-stent, a helical stent, or anannular ring.
 5. The prosthesis of claim 1, wherein the tubular branchis spaced from the proximal end of the prosthesis by a distance ofbetween about 5 mm and about 30 mm.
 6. The prosthesis of claim 1, wherea first portion of the branch extends from the point of attachment andinto the lumen of the main graft body and where a second portion of thetubular branch extends from the point of attachment externally to themain graft body.
 7. The prosthesis of claim 1, wherein the tubularbranch is positioned longitudinally at least partially between the peakof the first stent and the valley of the second stent andcircumferentially between adjacent struts of the first stent.
 8. Anendoluminal prosthesis comprising: a main graft body of graft material,the main graft body comprising: a sidewall, a proximal end, a distalend, and a lumen between the proximal end and the distal end; a firststent positioned near the proximal end of the main graft body, a secondstent positioned adjacent to and distal of the first stent, and a thirdstent distal of the second stent, each of the first stent and the secondstent comprising a peak and a valley and defining an area of graftmaterial between the peak of the first stent and the valley of thesecond stent; a slit in the sidewall positioned longitudinally betweenthe peak of the first stent and the valley of the second stent andextending at least partially circumferentially around the main graftbody, wherein the slit has a height that is parallel to a longitudinalaxis of the main graft body and a width that is perpendicular to thelongitudinal axis of the main graft body, wherein the width is greaterthan the height; and a tubular branch attached to the main graft body,the tubular branch comprising a first end opening and a second endopening, the tubular branch extending from the slit and attached to themain graft body at the slit at a point of attachment about acircumference of the tubular branch, the tubular branch being flexiblyorientable between a retrograde configuration and an antegradeconfiguration, wherein, in the retrograde configuration, the first endopening is oriented toward the distal end of the main graft body and thesecond end opening is oriented toward the proximal end of the main graftbody, and, in the antegrade configuration, the first end opening isoriented toward the proximal end of the main graft body and the secondend opening is oriented toward the distal end of the main graft body,wherein the proximal end of the main graft body comprises a slanted end,and a top longitudinal length of the main graft body is longer than abottom longitudinal length of the main graft body to form the slantedend.
 9. An endoluminal prosthesis comprising: a main graft body of graftmaterial, the main graft body comprising: a sidewall, a proximal end, adistal end, and a lumen between the proximal end and the distal end; afirst stent positioned near the proximal end of the main graft body, asecond stent positioned adjacent to and distal of the first stent, and athird stent distal of the second stent, each of the first stent and thesecond stent comprising a peak and a valley and defining an area ofgraft material between the peak of the first stent and the valley of thesecond stent; a slit in the sidewall positioned longitudinally betweenthe peak of the first stent and the valley of the second stent andextending at least partially circumferentially around the main graftbody, wherein the slit has a height that is parallel to a longitudinalaxis of the main graft body and a width that is perpendicular to thelongitudinal axis of the main graft body, wherein the width is greaterthan the height; and a tubular branch attached to the main graft body,the tubular branch comprising a first end opening and a second endopening, the tubular branch extending from the slit and attached to themain graft body at the slit at a point of attachment about acircumference of the tubular branch, the tubular branch being flexiblyorientable between a retrograde configuration and an antegradeconfiguration, wherein, in the retrograde configuration, the first endopening is oriented toward the distal end of the main graft body and thesecond end opening is oriented toward the proximal end of the main graftbody, and, in the antegrade configuration, the first end opening isoriented toward the proximal end of the main graft body and the secondend opening is oriented toward the distal end of the main graft body,wherein the area disposed between the first stent and the second stentis free of any stenting within the area and the graft material disposedin the area is under greater tension than the graft material outside ofthe area, and wherein the slit in the sidewall is positioned within thearea.
 10. An endoluminal prosthesis comprising: a main graft body ofgraft material, the main graft body comprising: a sidewall, a proximalend, a distal end, and a lumen between the proximal end and the distalend; a first stent positioned near the proximal end of the main graftbody, a second stent positioned adjacent to and distal of the firststent, and a third stent distal of the second stent, each of the firststent and the second stent comprising a peak and a valley and definingan area of graft material between the peak of the first stent and thevalley of the second stent; a slit in the sidewall positionedlongitudinally between the peak of the first stent and the valley of thesecond stent and extending at least partially circumferentially aroundthe main graft body, wherein the slit has a height that is parallel to alongitudinal axis of the main graft body and a width that isperpendicular to the longitudinal axis of the main graft body, whereinthe width is greater than the height; and a tubular branch attached tothe main graft body, the tubular branch comprising a first end openingand a second end opening, the tubular branch extending from the slit andattached to the main graft body at the slit at a point of attachmentabout a circumference of the tubular branch, the tubular branch beingflexibly orientable between a retrograde configuration and an antegradeconfiguration, wherein, in the retrograde configuration, the first endopening is oriented toward the distal end of the main graft body and thesecond end opening is oriented toward the proximal end of the main graftbody, and, in the antegrade configuration, the first end opening isoriented toward the proximal end of the main graft body and the secondend opening is oriented toward the distal end of the main graft body,wherein the first stent is attached to an inner surface of the maingraft body, the peak of the first stent comprises a series of peaks, oneof the series of peaks comprises a widened peak comprising a greaterangle than an adjacent peak, and the widened peak is circumferentiallyaligned with the tubular branch.
 11. An endoluminal prosthesiscomprising: a main graft body of graft material, the main graft bodycomprising: a sidewall, a proximal end, a distal end, and a lumenbetween the proximal end and the distal end; a first stent positionednear the proximal end of the main graft body, a second stent near theproximal end of the main body positioned adjacent to and distal of thefirst stent, and a third stent distal of and axially spaced from thesecond stent, each of the first stent and the second stent comprising apeak and a valley and defining an area of graft material; a slit in thesidewall of graft material positioned longitudinally between the peak ofthe first stent and the valley of the second stent and extending atleast partially circumferentially around the main graft body, whereinthe slit has a height that is parallel to a longitudinal axis of themain graft body and a width that is perpendicular to the longitudinalaxis of the main body, wherein the width is greater than the height; anda tubular branch attached to the main graft body, the tubular branchcomprising a first end opening and a second end opening, the tubularbranch extending from the slit and attached to the main graft body atthe slit at a point of attachment about a circumference of the tubularbranch, wherein a first portion of the tubular branch extends from thepoint of attachment and into the lumen of the main graft body and asecond portion of the tubular branch extends from the point ofattachment externally to the main graft body, and wherein the tubularbranch is flexibly orientable between a retrograde configuration and anantegrade configuration, wherein, in the retrograde configuration, thefirst end opening is oriented toward the distal end of the main graftbody and the second end opening is oriented toward the proximal end ofthe main graft body, and, in the antegrade configuration, the first endopening is oriented toward the proximal end of the main graft body andthe second end opening is oriented toward the distal end of the maingraft body.
 12. An endoluminal prosthesis comprising: a main graft bodyof graft material, the main graft body comprising: a sidewall, aproximal end, a distal end, and a lumen between the proximal end and thedistal end; a first stent positioned near the proximal end of the maingraft body, a second stent positioned adjacent to and distal of thefirst stent, and a third stent distal of the second stent, each of thefirst stent and the second stent comprising a peak and a valley anddefining an area of graft material between the peak of the first stentand the valley of the second stent; a slit in the sidewall positionedlongitudinally between the peak of the first stent and the valley of thesecond stent and extending at least partially circumferentially aroundthe main graft body, wherein the slit has a height that is parallel to alongitudinal axis of the main graft body and a width that isperpendicular to the longitudinal axis of the main graft body, whereinthe width is greater than the height; and a tubular branch attached tothe main graft body, the tubular branch comprising a first end openingand a second end opening, the tubular branch extending from the slit andattached to the main graft body at the slit at a point of attachmentabout a circumference of the tubular branch, the tubular branch beingflexibly orientable between a retrograde configuration and an antegradeconfiguration, a fourth stent positioned near the proximal end of themain graft body, wherein the first stent is attached to an inner surfaceof the main graft body, the fourth stent is attached to an outer surfaceof the main graft body and comprises a series of peaks, the fourth stentat least partially overlaps the first stent, a first peak of the fourthstent is circumferentially aligned with each of the tubular branch andthe peak of the first stent, and a second peak of the fourth stent iscircumferentially aligned with the valley of the first stent, wherein,in the retrograde configuration, the first end opening is orientedtoward the distal end of the main graft body and the second end openingis oriented toward the proximal end of the main graft body, and, in theantegrade configuration, the first end opening is oriented toward theproximal end of the main graft body and the second end opening isoriented toward the distal end of the main graft body.
 13. Anendoluminal prosthesis comprising: a main graft body of graft material,the main graft body comprising: a sidewall, a proximal end, a distalend, and a lumen between the proximal end and the distal end; a firststent positioned near the proximal end of the main graft body, a secondstent positioned adjacent to and distal of the first stent, and a thirdstent distal of the second stent, each of the first stent and the secondstent comprising a peak and a valley and defining an area of graftmaterial between the peak of the first stent and the valley of thesecond stent; a slit in the sidewall positioned longitudinally betweenthe peak of the first stent and the valley of the second stent andextending at least partially circumferentially around the main graftbody, wherein the slit has a height that is parallel to a longitudinalaxis of the main graft body and a width that is perpendicular to thelongitudinal axis of the main graft body, wherein the width is greaterthan the height; and a tubular branch attached to the main graft body,the tubular branch comprising a first end opening and a second endopening, the tubular branch extending from the slit and attached to themain graft body at the slit at a point of attachment about acircumference of the tubular branch, the tubular branch being flexiblyorientable between a retrograde configuration and an antegradeconfiguration, a fourth stent positioned near the proximal end of themain graft body, wherein each of the first stent and the fourth stent isattached to a surface of the main graft body, the peak of the firststent comprises a series of peaks, the valley of the first stentcomprises a series of valleys, the fourth stent comprises a series ofpeaks and a series of valleys, the fourth stent comprises a shorteramplitude than the first stent and a greater number of peaks and valleysthan the first stent, the fourth stent is positioned proximal of thefirst stent, and the first stent and the fourth stent are in a nestedrelationship with one another, wherein, in the retrograde configuration,the first end opening is oriented toward the distal end of the maingraft body and the second end opening is oriented toward the proximalend of the main graft body, and, in the antegrade configuration, thefirst end opening is oriented toward the proximal end of the main graftbody and the second end opening is oriented toward the distal end of themain graft body.
 14. An endoluminal prosthesis comprising: a main graftbody, the main graft body comprising a proximal end, a distal end, and alumen therebetween; a slit in the main graft body, the slit extending atleast partially circumferentially around the main graft body, whereinthe slit has a height that is parallel to a longitudinal axis of themain graft body and a width that is perpendicular to the longitudinalaxis of the main body, wherein the width is greater than the height, anda tubular branch disposed in the slit and comprising a first portionextending inward from the slit into the lumen of the main graft body, asecond portion extending outward from the slit to the exterior of themain graft body, and an intermediate portion between the first andsecond portions that is attached to the main graft body at the slit,wherein the width of the slit comprises a length of between about ⅖ of acircumference of the tubular branch and about ½ of the circumference ofthe tubular branch; wherein the tubular branch is sewn into the slitbetween the first and second portions; wherein the second portion of thetubular branch is flexibly orientable toward the proximal end or thedistal end of the main graft body.
 15. The prosthesis of claim 14,further comprising a stent positioned near the proximal end of the maingraft body, wherein the slit is positioned within a peak of the stentand circumferentially between adjacent struts of the stent.
 16. Theprosthesis of claim 14, further comprising a stent attached to the maingraft body and comprising a peak and a valley, wherein the peak of thestent is spaced from the proximal end of the main graft body by adistance of less than about 2 mm, and the slit is spaced from theproximal end of the main graft body by a distance of between about 5 mmand about 30 mm.